Ring resonators typically have a loop waveguide optically coupled with a bus (input/output) waveguide. These resonators are configured to resonate at a particular wavelength. When light of the resonance wavelength passes the ring resonator in the bus waveguide, that light is coupled from the bus waveguide into the ring resonator. The resonance wavelength is typically the wavelength of a particular optical channel. As a result, when that optical channel is present in the bus waveguide, that optical channel is coupled into the loop waveguide. Accordingly, that optical channel can be demultiplexed from other optical channels in the bus waveguide.
The limitations in the fabrication process for these resonators often cause them to resonate at a wavelength other than the intended wavelength. As a result, the device often fail to couple the desired channel or couple that channel with less efficiency than is desired.
For the above reasons, there is a need for an improved ring resonator.